There is a Human Trafficking section in the well known collection of OSINT.
PDF available for download from here:
https:// phibetaiota.net/2012/09/2012-ben-benavides-osint-links-directory-2-0-2oolkit-on-the-go/
Robert Steele, who runs the site, is a well-known OSINT and anti-human trafficking advocate, among many other things.